McKinley Eliot T, Watchmaker Jennifer M, Chakravarthy A Bapsi, Meyerhardt Jeffrey A, Engelman Jeffrey A, Walker Ronald C, Washington M Kay, Coffey Robert J, Manning H Charles
Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical School, 1161 21st Ave. S., AA1105 MCN, Nashville, TN, 37232-2310, USA.
Ann Nucl Med. 2015 Jul;29(6):535-42. doi: 10.1007/s12149-015-0974-6. Epub 2015 Apr 22.
This pilot study evaluated the utility of 3'-deoxy-3'[18F]-fluorothymidine ([(18)F]-FLT) positron emission tomography (PET) to predict response to neoadjuvant therapy that included cetuximab in patients with wild-type KRAS rectal cancers.
Baseline [(18)F]-FLT PET was collected prior to treatment initiation. Follow-up [(18)F]-FLT was collected after three weekly infusions of cetuximab, and following a combined regimen of cetuximab, 5-FU, and radiation. Imaging-matched biopsies were collected with each PET study.
Diminished [(18)F]-FLT PET was observed in 3/4 of patients following cetuximab treatment alone and in all patients following combination therapy. Reduced [(18)F]-FLT PET following combination therapy predicted disease-free status at surgery. Overall, [(18)F]-FLT PET agreed with Ki67 immunoreactivity from biopsy samples and surgically resected tissue, and was predictive of treatment-induced rise in p27 levels.
These results suggest that [(18)F]-FLT PET is a promising imaging biomarker to predict response to neoadjuvant therapy that included EGFR blockade with cetuximab in patients with rectal cancer.
本初步研究评估了3'-脱氧-3'[18F]-氟胸腺嘧啶核苷([(18)F]-FLT)正电子发射断层扫描(PET)在预测野生型KRAS直肠癌患者对含西妥昔单抗的新辅助治疗反应中的效用。
在开始治疗前收集基线[(18)F]-FLT PET。在每周输注3次西妥昔单抗后,以及在西妥昔单抗、5-氟尿嘧啶和放疗联合方案治疗后收集随访[(18)F]-FLT。每次PET检查时均采集影像匹配的活检样本。
单独使用西妥昔单抗治疗后,3/4的患者[(18)F]-FLT PET信号减弱,联合治疗后的所有患者均如此。联合治疗后[(18)F]-FLT PET信号减弱可预测手术时的无病状态。总体而言,[(18)F]-FLT PET与活检样本及手术切除组织中的Ki67免疫反应性一致,并可预测治疗引起的p27水平升高。
这些结果表明,[(18)F]-FLT PET是一种有前景的成像生物标志物,可用于预测直肠癌患者对含西妥昔单抗的表皮生长因子受体阻断新辅助治疗的反应。